JPH11119444A - Resist stripping solution composition and resist stripping method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist stripping solution composition permitting both of a resist film and a modifying film to be enhanced in strippability, and both of substrates having metal films, especially of Al or its alloy, or of Ti formed on them to effectively prevent corrosion under high temperature conditions, and to provide a resist stripping method using it. SOLUTION: This resist stripping solution composition comprises (a) 2-30 weight % hydroxyamines, (b) 2-35 weight % water, (c) 25-40 weight % monoethanolamine and/or diethanolamine, (d) 20-32 weight % dimethyl sulfoxide, and (e) 2-20 weight % aromatic hydroxyl compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resist stripping composition and a resist stripping method using the same. More specifically, it is suitable for use in the manufacture of semiconductor devices such as ICs and LSIs or liquid crystal panel devices, and has excellent exfoliation properties of both a resist film and a deteriorated film, and excellent corrosion prevention of a substrate even under high temperature processing conditions. The present invention relates to a stripping composition and a resist stripping method using the same.

[0002]

2. Description of the Related Art For semiconductor elements such as ICs and LSIs and liquid crystal panel elements, a photoresist is uniformly coated on a conductive metal film such as a Nesa film or an insulating film such as a SiO ₂ film formed on a substrate by vapor deposition or the like. Then, this is exposed and developed to form a resist pattern. Using the pattern as a mask, the conductive metal film or the insulating film is selectively etched to form a fine circuit, and then an unnecessary resist layer is peeled off. Manufactured by removing with a liquid. Here, other examples of the metal film include aluminum (Al); aluminum-silicon (Al-S).
i), aluminum-silicon-copper (Al-Si-Cu)
And other aluminum alloys (Al alloys); pure titanium (T
i): A titanium alloy (Ti alloy) such as titanium nitride (TiN) or titanium tungsten (TiW) is used, and these are formed on the substrate in a single layer or a plurality of layers.

In recent years, a resist stripping composition using an alkanolamine has been used as a stripping composition for removing the resist layer (JP-A-64-2935).
No. 5, JP-A-63-208043, etc.).

However, in today's manufacturing process of semiconductor devices and liquid crystal devices, in addition to the above-mentioned method, it is necessary to peel off a resist film whose resist layer has been subjected to dry etching, ashing, ion implantation and the like. I have. By these processes, the resist film after the process becomes an altered film. In recent years, these processing conditions have become more severe, and the deteriorated film has been changed from an organic film to a film having inorganic properties. Therefore, a stripping solution composition using alkanolamines has an adverse effect on the releasability of the deteriorated film. It is enough.

[0005] However, recently, a resist stripping composition containing hydroxylamines has been proposed as a resist stripping composition having more excellent stripping properties of the deteriorated film. For example, JP-A-4-289866 describes a resist stripping composition containing hydroxylamine and alkanolamine. Also, JP-A-6
JP-266119 discloses a resist stripping composition in which hydroxylamine and alkanolamine further contain a chelating agent (corrosion inhibitor) such as catechol.

[0006] The stripping solution composition containing these hydroxylamines improves the releasability of the deteriorated film as compared with the stripping solution using the above-mentioned alkanolamines.
There is a problem that corrosion appears on a substrate on which an Al alloy such as l-Si or Al-Si-Cu is deposited or on a substrate on which pure titanium (Ti) is deposited. Actually, Japanese Patent Application Laid-Open No. 6-2
The stripping solution described in JP-A-66199 can prevent corrosion of a titanium alloy, but cannot prevent corrosion of pure titanium (Ti), and has a problem that corrosion occurs.

[0007] To solve the above problems, see, for example, JP-A-9-96.
No. 911 discloses a resist stripping composition containing a specific amount of hydroxylamines, water, amines having a predetermined acid dissociation constant, a water-soluble organic solvent, and an anticorrosive. And excellent anticorrosion effect on substrates formed with Al, Al alloy, or pure titanium (Ti). However, the stripping solution composition for resists described in this publication is not sufficient in stripping properties of the resist film.

In recent years, from the viewpoint of working efficiency and the like, a peeling operation at a higher temperature has been required more than ever before. Generally, the higher the temperature, the better the releasability. However, on the other hand, the metal film on the substrate tends to be corroded more easily. Further, there has been an increasing demand for a stripping solution composition that can cope with stripping of both a resist film and a deteriorated film under high-temperature processing conditions.

Therefore, it has excellent releasability for both the resist film and the deteriorated film, and under a higher temperature treatment condition, a metal film, especially Al or Al alloy,
It has been desired to develop a resist stripper that can effectively prevent corrosion of a substrate formed with Ti.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to form a metal film, particularly Al or an Al alloy, even under a higher temperature treatment condition. Substrate or pure titanium (T
A resist stripping solution composition which can effectively prevent corrosion on both of the substrates on which i) is formed and has excellent stripping properties on both the resist film and the deteriorated film, and using the same. An object of the present invention is to provide a resist stripping method.

[0011]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have identified hydroxylamines, water, specific amines, dimethyl sulfoxide, and aromatic hydroxy compounds. It has been found that the above-mentioned problems can be solved by using a resist stripper composition mixed in proportions, and the present invention has been completed based on this.

That is, the present invention provides (a) 2 to 30% by weight of hydroxylamines, (b) 2 to 35% by weight of water,
(C) 25-40% by weight of at least one selected from monoethanolamine and diethanolamine,
The present invention relates to a resist stripping composition comprising (d) 20 to 32% by weight of dimethyl sulfoxide and (e) 2 to 20% by weight of an aromatic hydroxy compound.

The present invention also provides a step of providing a resist layer on a substrate having a metal layer formed thereon, a step of selectively exposing the resist layer, a step of forming a resist pattern by developing the exposed resist layer, Etching the substrate using the pattern as a mask, and, if desired, a step of peeling the resist pattern after the etching from the substrate, and a step of peeling the resist pattern after etching or ashing from the substrate. The stripper composition for use at a temperature of 75
The present invention relates to a resist stripping method characterized by stripping a resist pattern after etching or ashing by using a temperature in the range of up to 85 ° C.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the resist stripping composition of the present invention will be described in detail.

In the present invention, "Ti" means "pure titanium" and does not include titanium alloys such as titanium nitride (TiN) and titanium tungsten (TiW).

The hydroxylamines as the component (a) are represented by the following general formula (I)

[0017]

Embedded image

(Wherein R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group having 1 to 6 carbon atoms).

Here, the lower alkyl group having 1 to 6 carbon atoms includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group,
Examples include tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, and 2,3-dimethylbutyl. Is done. R ¹ and R ² may be the same or different.

Specific examples of the above-mentioned hydroxylamines include hydroxylamine (NH ₂ OH), N-methylhydroxylamine, N, N-dimethylhydroxylamine, N, N-diethylhydroxylamine and the like. Among them, hydroxylamine is preferably used. These hydroxylamines may be used alone or in combination of two or more.

The water as the component (b) is inevitably contained in the component (a), but the amount of water may be further adjusted.

As the component (c), at least one selected from monoethanolamine and diethanolamine is used.

As the component (d), dimethyl sulfoxide is used.

The aromatic hydroxy compound as the component (e) is mainly for obtaining an anticorrosive effect, and specifically includes phenol, cresol, xylenol, catechol (= 1,2-dihydroxybenzene), tert-butyl. Catechol, resorcinol, hydroquinone, pyrogallol, 1,2,4-benzenetriol, salicyl alcohol, p-hydroxybenzyl alcohol, o-hydroxybenzyl alcohol, p-hydroxyphenethyl alcohol, p-aminophenol, m-aminophenol, diaminophenol , Aminoresorcinol,
p-hydroxybenzoic acid, o-hydroxybenzoic acid,
Examples thereof include 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and 3,5-dihydroxybenzoic acid. Among them, catechol and tert-butyl catechol are preferably used, and tert-butyl catechol is more preferably used from the viewpoint of work safety and the like. These compounds may be used alone or in combination of two or more.

The mixing ratio of the above components (a) to (e) is
Component (a) is 2 to 30% by weight, preferably 5 to 20% by weight, and component (b) is 2 to 35% by weight, preferably 5 to 25%.
% By weight, component (c) is 25 to 40% by weight, preferably 3% by weight.
0 to 35% by weight, component (d) is 20 to 32% by weight, preferably 25 to 30% by weight, and component (e) is 2 to 20% by weight, preferably 3 to 10% by weight. In the present invention, the mixing ratio of the components (a) to (e) is important,
By setting the compounding amount of each component within the above range, both the resist film and the deteriorated film can be effectively stripped, and even if the stripping process is performed at a high temperature of about 75 to 85 ° C., the metal Does not corrode the film. Among the components, if the amount of component (c) exceeds 40% by weight, the releasability of both the resist film and the deteriorated film is improved, but corrosion occurs on the substrate on which Al or the Al alloy is formed,
On the other hand, when the component (c) is less than 25% by weight, corrosion occurs on the substrate on which Ti is formed.

The resist stripping composition of the present invention can be advantageously used for resists that can be developed with an aqueous alkaline solution, including negative and positive resists. Examples of such a resist include (i) a positive resist containing a naphthoquinonediazide compound and a novolak resin, (ii) a compound that generates an acid upon exposure, a compound that is decomposed by an acid to increase solubility in an aqueous alkali solution, and an alkali-soluble compound. A positive resist containing a resin, (iii) a compound that generates an acid upon exposure, a positive resist containing an alkali-soluble resin having a group that is decomposed by an acid and increases the solubility in an alkaline aqueous solution, and (iv) light Examples include, but are not limited to, a negative resist containing a compound that generates an acid, a crosslinking agent, and an alkali-soluble resin.

The resist stripping method of the present invention is divided into a case where a resist pattern obtained by a lithography method is formed and then a resist film after etching is stripped and a case where an altered film after ashing is stripped.

As an example of the former case of stripping the resist film after etching, (I) a step of applying a resist composition on a substrate on which a metal layer is formed, drying and forming a resist layer;
(II) selectively exposing the resist layer through a mask pattern, (III) providing a resist pattern by developing the exposed resist layer, and (IV) etching the substrate using the resist pattern as a mask. And (V) stripping the resist pattern after etching from the substrate, wherein the resist stripping composition of the present invention is heated to a temperature of 75 to 85.
A method in which the resist pattern after etching is peeled off using the temperature range of ° C.

As an example of the latter case of peeling off the altered film after ashing, (I) a step of applying a resist composition on a substrate on which a metal layer is formed and drying to provide a resist layer; Selectively exposing the layer through a mask pattern, (III) providing a resist pattern by developing the exposed resist layer, (IV) etching the substrate using the resist pattern as a mask, (V) A) ashing the resist pattern;
And (VI) a step of removing the resist pattern after ashing from the substrate.
A method of stripping the resist pattern after ashing by using the resist stripping composition of the present invention at a temperature in the range of 75 to 85 ° C.

As the substrate on which the metal layer is formed, aluminum (Al); aluminum-silicon (Al-Si),
Aluminum alloy (Al alloy) such as aluminum-silicon-copper (Al-Si-Cu); pure titanium (Ti); titanium nitride (TiN), titanium tungsten (Ti)
This is a substrate on which a metal film such as a titanium alloy (Ti alloy) such as W) is formed. In particular, the peeling method of the present invention provides a substrate having at least a pure titanium (Ti) layer as a metal layer, for example, a titanium nitride (TiN) layer as a first layer on the substrate.
Next, a pure titanium (Ti) layer is formed as a second layer on the first layer, and Al-Si-C is formed as a third layer on the second layer.
A substrate having a u layer and a TiN layer formed as a fourth layer on the third layer has an effect that the corrosion prevention effect of the pure titanium (Ti) is extremely excellent.

Coating, drying, exposure, development, etching and ashing are all conventional means and are not particularly limited. The etching may be either wet etching or dry etching, or a combination of both. Ashing is originally a method of removing a resist pattern. However, ashing often leaves a resist pattern partially as a deteriorated film, and the present invention is effective in completely removing the deteriorated film in such a case.

The developing step (III), (V)
Alternatively, after the peeling step (VI), a rinsing process and a drying process using commonly used pure water or lower alcohol may be performed.

Depending on the type of the resist, a post-exposure bake, which is a post-exposure bake usually performed on a chemically amplified resist, may be performed. Further, post baking after forming the resist pattern may be performed.

The peeling treatment is usually performed by a dipping method or a spray method. The temperature of the stripping solution at that time is usually 50 to
Although performed at 85 ° C., the stripping method using the stripping solution composition of the present invention has a high corrosion prevention effect on a metal film even at a high temperature of 75 to 85 ° C., and is excellent in strippability of a resist film and a deteriorated film. Further, the peeling time is not particularly limited as long as it is a sufficient time for peeling,
Usually, it is about 10 to 20 minutes.

[0035]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Examples 1 to 5, Comparative Examples 1 to 5) A TiN layer as a first layer, a pure titanium (Ti) layer as a second layer, and an Al—Si—C layer as a third layer are sequentially formed on a silicon wafer.
A u-layer is coated on a substrate having a TiN layer as a fourth layer with THMR-iP3300 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a positive photoresist made of a naphthoquinonediazide compound and a novolak resin, using a spinner, and heated to 90 ° C. 9
Pre-baking was performed for 0 second to form a resist layer having a thickness of 2.0 μm. This resist layer was NSR-2005i1
The resultant was exposed through a mask pattern using 0D (manufactured by Nikon Corporation) and developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) to form a resist pattern. Next, post-baking was performed at 120 ° C. for 90 seconds.

[Resistability Test of Resist Film] Next, the silicon wafer having the resist pattern formed under the above conditions was subjected to dry etching. This was immersed in a stripping solution composition of each composition shown in Table 1 at 80 ° C. for 20 minutes to perform a resist film stripping process. The substrate after the peeling treatment is sufficiently rinsed with pure water, and the peelability of the resist film and the state of corrosion of the first to fourth metal film layers are measured by SEM.
(Scanning electron microscope) Evaluation was made by observing photographs. Table 1 shows the results. Note that all of the TiN in the first and fourth layers did not corrode, so the description in Table 1 was omitted.

[Removability Test of Degraded Film] A resist pattern was formed and a silicon wafer was dry-etched by the same operation as in the above-described resist film removability test.

Next, the resist pattern was subjected to a plasma ashing process using an ashing apparatus “TCA-3822” (manufactured by Tokyo Ohka Kogyo Co., Ltd.) with oxygen gas at 150 ° C. for 60 seconds, but an ashing residue (altered film) was found. Was.

Subsequently, the treated silicon wafer was immersed in a stripping solution composition of each composition shown in Table 1 at 80 ° C. for 20 minutes, and a deteriorated film was stripped. The substrate after the peeling treatment is sufficiently rinsed with pure water, and the peeled state of the deteriorated film and the corrosion state of the first to fourth metal film layers are evaluated by observing SEM (scanning electron microscope) photographs. did. Table 1 shows the results. The first and fourth layers of Ti
For N, there was no corrosion, so the description in Table 1 was omitted.

The peelability of the resist film and the deteriorated film was evaluated as follows.

◎: good peelability ：: some residue remained Δ: many residues remained The corrosion state was evaluated as follows.

◎: Almost no corrosion ○: Slight corrosion was observed △: Considerable corrosion was observed

[0044]

[Table 1]

[0045]

As described in detail above, according to the present invention, even under a high-temperature peeling condition, a resist film and a deteriorated film formed by processing such as dry etching, ashing and ion implantation under more severe conditions are used. Provided is a resist stripping composition and a resist stripping method using the same, which are excellent in both stripping properties and excellent in corrosion prevention effect on both a substrate on which Al or an Al alloy is formed or a substrate on which Ti is formed. It has the effect that it can be done.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toshimasa Nakayama 150 Nakamurako, Nakahara-ku, Kawasaki City, Kanagawa Prefecture

Claims (6)

[Claims] (1) 2 to 30% by weight of hydroxylamines, (b) 2 to 35% by weight of water, (c) 25 to 40% by weight of at least one selected from monoethanolamine and diethanolamine. %, (D) 20 to 32% by weight of dimethyl sulfoxide, and (e) 2 to 20% by weight of an aromatic hydroxy compound. 2. The method according to claim 1, wherein component (a) is hydroxylamine (NH).
_2. The resist stripping composition according to claim 1, which is ₂ OH). 3. The resist stripping composition according to claim 1, wherein the component (e) is at least one selected from catechol and tert-butyl catechol. 4. A step of providing a resist layer on a substrate on which a metal layer is formed, a step of selectively exposing the resist layer, and a step of forming a resist pattern by developing the exposed resist layer. 4. A resist stripping method comprising: (IV) a step of etching the substrate using the resist pattern as a mask; and (V) a step of stripping the etched resist pattern from the substrate. A resist stripping method, wherein the resist pattern after etching is stripped by using the resist stripping composition according to (1) in a temperature range of 75 to 85 ° C. 5. A step of providing a resist layer on a substrate having a metal layer formed thereon, a step of selectively exposing the resist layer, and a step of forming a resist pattern by developing the exposed resist layer. (IV) a step of etching the substrate using the resist pattern as a mask;
(V) a step of ashing a resist pattern; and (VI) a step of removing a resist pattern after ashing from a substrate. A resist stripping method, wherein the resist pattern after ashing is stripped at a temperature of 75 to 85 ° C. 6. A method according to claim 4, wherein the metal layer formed on the substrate has at least a pure titanium (Ti) layer.